Dictionary of Antarctic slang

U-barrel
A 55 gal. drum used for the collection of urine in places that lack real plumbing. U-Barrels are painted canary yellow, lest someone mistake the contents for something useful, like fuel or drinking water. The actual accomodations for filling one range from a bathroom with a tin-lined wooden box complete with standard toilet seat (B-133) to a pile of rocks to stand on and a funnel weighted down with a rock so it doesn't blow away ( Lake Hoare).

The things one learns on the internets...

Link: Dictionary of Antarctic slang.